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Cut down to one GCD and clarified variable names, getting more explicit about what's going on.

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This commit is contained in:
Thomas Harte 2016-09-18 10:24:09 -04:00
parent 6f0b9adc3d
commit 8c2bf099ad
2 changed files with 20 additions and 19 deletions
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37
Storage/TimedEventLoop.cpp
View File

@ -31,20 +31,13 @@ unsigned int TimedEventLoop::get_cycles_until_next_event()
void TimedEventLoop::reset_timer()
{
_error.set_zero();
_subcycles_until_event.set_zero();
_cycles_until_event = 0;
}
void TimedEventLoop::reset_timer_to_offset(Time offset)
{
/* unsigned int common_clock_rate = NumberTheory::least_common_multiple(offset.clock_rate, _event_interval.clock_rate);
_time_into_interval = offset.length * (common_clock_rate / offset.clock_rate);
_event_interval.length *= common_clock_rate / _event_interval.clock_rate;
_event_interval.clock_rate = common_clock_rate;
if(common_clock_rate != _stepper->get_output_rate())
{
_stepper.reset(new SignalProcessing::Stepper(_event_interval.clock_rate, _input_clock_rate));
}*/
// TODO: apply
}
void TimedEventLoop::jump_to_next_event()
@ -55,19 +48,27 @@ void TimedEventLoop::jump_to_next_event()
void TimedEventLoop::set_next_event_time_interval(Time interval)
{
unsigned int common_divisor = NumberTheory::greatest_common_divisor(_error.clock_rate, interval.clock_rate);
uint64_t denominator = (interval.clock_rate * _error.clock_rate) / common_divisor;
uint64_t numerator = (_error.clock_rate / common_divisor) * _input_clock_rate * interval.length - (interval.clock_rate / common_divisor) * _error.length;
// Calculate [interval]*[input clock rate] + [subcycles until this event].
int64_t denominator = (int64_t)interval.clock_rate * (int64_t)_subcycles_until_event.clock_rate;
int64_t numerator =
(int64_t)_subcycles_until_event.clock_rate * (int64_t)_input_clock_rate * (int64_t)interval.length +
(int64_t)interval.clock_rate * (int64_t)_subcycles_until_event.length;
// Simplify now, to prepare for stuffing into possibly 32-bit quantities
int64_t common_divisor = NumberTheory::greatest_common_divisor(numerator % denominator, denominator);
denominator /= common_divisor;
numerator /= common_divisor;
// So this event will fire in the integral number of cycles from now, putting us at the remainder
// number of subcycles
_cycles_until_event = (int)(numerator / denominator);
_error.length = (unsigned int)(numerator % denominator);
_error.clock_rate = (unsigned int)denominator;
_error.simplify();
_subcycles_until_event.length = (unsigned int)(numerator % denominator);
_subcycles_until_event.clock_rate = (unsigned int)denominator;
}
Time TimedEventLoop::get_time_into_next_event()
{
Time result = _event_interval;
// result.length = _time_into_interval;
return result;
// TODO: calculate, presumably as [length of interval] - [cycles left] - [subcycles]
Time zero;
return zero;
}

2
Storage/TimedEventLoop.hpp
View File

@ -89,8 +89,8 @@ namespace Storage {
private:
unsigned int _input_clock_rate;
int _cycles_until_event;
Time _subcycles_until_event;
Time _event_interval;
Time _error;
};
}